Back pressure plug valve



Dec. 13, 1938. A, L, STONE BACK PRESSURE PLUG VALVE Filed Aug. 24, 1936 Inverzfar fllberfl. Stone.

Patented Dec. 13, 1938 e e t I p e UNITED STATES PATENT OFFICE v I BACK PRESSUREP-LUG VALVE Albert L. Stone, Palos Verdes Estates, Calih, as-

, signor to Hydril Company, Los-Angeles, Calif;,-a orporation. of California v r v "Application August 24, 1936, Serial Nd-91,631,

16Olaims. l (c1, 166-13) 7 This invention relates generally to improvepositions of the parts when an .upwardepressure ments in well pipe plugs or closures adapted to. is applied to the device; t be dropped or forced downwardly through the Fig. 3 is a fragmentary sectional viewillustratpipeto a desired or predetermined depth to close ing avariant form of the invention; and

the pipe against upward fluid flow. More specif- Fig. 4 is an enlarged sectionon line L4 of 5' ically. the invention has to do with adrop-in or Fig. 2. a i u v pump-down type'b'ack pressure valve for use in o, In the rawing, I have shown alower portion drilling operations to seal the drill pipe against -of.the drill pipe string Hllwithin the wellcasing the escape of well fluid in situations where the the p pe S r Comprising P p lengths l2 standard back pressure valve failsor is not used, connectedby a special coupling 13 located at or or to provide an additional precaution against near the usual drill collar and above a'suitable fluid escape at a time when the back pressure back pressurevalve,forexample of the type illusvalve may still be in good condition. trated at M in Fig.3. As explained above, the

The usual back pressure valve. is carried by function of this back pressure valve 14 is to'per- 15 the drill string at or near its lower end, and the mitdownward fluid circulation through the drill 15 function of the valve is to pass the downward string, but prevent upward escape of well-fluid circulation but to close the pipe against escape through the d l S ri a Where e Well e of well fiuid during drilling operations and while ops sudden pressurer- Any desired type of standthe pipe string is being lowered into or pulledv am back pressure valve may beused, The typifrom the "well. @My general object is to provide cal form shown in Fig. 3 comprises, a cylindric 20 a back pressure valve device that, may be dropped body 15 inserted withinthe bore of coupling l6 or forced by fluid pressure down through the pipe and clamped between shoulder I! and the lower to a predetermined position above the stationary fpin end I2a of the pipe l2 below coupling 13.

. 'backpressure valve, thus afiording a safety check Body I5 contains an axially offset bore l8 pre inthe event the latter fails to functionv properly. senting an inclined shoulder;,l9- and a lower re- 25 In its preferred form, the present device com- Y duced diameter portion l8a. A float valve20 is prises a body carrying aradially expansible packpivotedat 2| on the lower end of body; I 5, the ex, a valve controlled passage through the body, valvenormally being swung open to the point of and means expansible into engagement with the engagement of the valve carried arm zlla vwith pipe by upwardly directedfluid pressure, to hold thecoupling wall, but seating toclose the lower 30 g the device against upward movement. v end of bore l8 in response to sudden upward fluid The device may be inserted in the drill pipe and p S e 0 rise of hquidin the drill st n v dropped or forced down to seating position at Couplin l3 has h a d ext aLflus -typ a time when the standard back pressurevalve' joints t Z2-Wi h the drill p pe I; th coupling is in good working'condition, as, for example dur- W bo e 2 b g o uniferm diameter. d the pp 35v ing the time the circulating mud is being re- Lpin e of t e up na n beveledat 3 t0 placed with water before pulling the drillstringa li t e y t pb k pressurevalve The drop-in valve device willreach its seat and, inteb re 23. :Th d pn a k pr ssur va v remain in condition for the pipe'eng aging means generally indicated e .P e S an on ate 40 and pack r t b fgr'ced int n gem t. t tubular body 26 having ab'ore 2'|,the-lower end 4 the pipe to close the same, in the event the stand-o o w ch i C o ed bya'chee Valve m s pard back pressure valve later fails. The device ward y a ains s e byc l prln 2 upported may be inserted in the usual lubricator pipeabove h a tapered e bushing Dlllfihg, drilling the Kelly cock and pumped downer merely al- 'operations,, circulating fluid is discharged downi lowed to drop until it reaches'seating' position; wardly thr ugh the bore 21 Pa va ve .18 and 45 The various structural and functional aspects outwardly thr ugh Slots .7 indicated; y he of the invention will be more fully understood W into the drill ne e w, but n from the following detailed description, in which culation is discontinued, the. valve seatsto prereference is had to the accompanying drawing vent'upward flow of well fluld'jthrough the body 5o thatis illustrative of theinventionin certain typi-f bore. V 4

cal and preferred forms, a Y The body, 26 has an upper reduced diameter Fig. 'l'is a sectional view showing the drop-in an r l P rti n 2, about which P t er back pressure valve device seated on the stop dially expa'nsible packer 33, and,above the packer suitable pipe engagingmeans, generally indicated shoulder within a pipe coupling; g g Fig. 2 is a view similar to Fig. 1 showingthe' at ,operate's to hold the deviceagainstupward, u

" the bore 21, past cheek -valve "and through the back pressure valve below. So longas the back pressure valve is in good condition, holding the a well pressure and cl'osing the drill string against I ment with the coupling bore wall.

38, the mandrel being movable upwardly relative to the sleeve and ring assembly from the position 01' Fig. lain which ring-'38 engages-a nut 33 threaded and held in flxedposition. by set screw 40 on the upper end of theJmandrel.

Sleeve 38 carries a plurality of circularly arranged wedge slips ll, typically three or four in number, contained in vertically-extending ways 32, with side flanges on the slips received within inclined grooves 42a, see Fig. 4. The outer serrated faces 33 or the slipsare substantially vertical and the back surfaces of the slips engage the inclined wedge surfaces '33 so that as the carrier sleeve moves upwardly relative to the slips, the latter expand into engagement with the coupling bore wall. 'It may be desirable, in orderto insure a" secure grip by" the slips on the coupling, to form annularserrationsliin the coupling wall oppo-' site thesiips.

As best illustrated in Fig. 2, the body is has at 'its point of maximum diameter 'a'downwardly iacing annular shoulder adapted to seat upon shoulder 41 on the upper end 01 a bushing 48 .that maybe threaded into or otherwise positioned within the lower end of coupling l3, to arrest downward movement of the drop-in valve assembly below the position of Fig. '1.

'In operation, the device is inserted within the drill string, as previously indicated, and dropped;

or forced down by fluid pressure throughjv the 7 string and into coupling I; to 'the'seating posi tion oi- Fig. 1, in which shoulder-l6 engages" shoulder I1 021 the upper end ofthe-bushing'. With the device} in seated position, downward circulation or fluid may be maintained through upward fluid flow, the parts of the'drop in device will remainin the positions of Fig. 1. If, however,

at any time 'the' back pressure valve 'iailsf oidevelops substantial leakage, the resultant application 01- well pressure to the lower end-oi body" or the drop-in device, causes the'pipe gripping means 33 to be expanded to 'hold the ,device against upward displacement in the coupling, and 1 packer 33' to be expanded intofluid tighten'gage Applicationoii well pressure to the lower end oi" the device results in upward movementot the mandrel 32, together with packer 33 and'carrier sleeve '36, causing the slips 3| to be expanded 1 into gripping engagement with the coupling serrations. i At that point, sleeve 33 and ring 31 become held against upward movement, with the result that as the-mandrel is forced further up-' wardly by the fluid pressure', the packer is expanded into'tight engagement with the borelwall by wedging, coaction between tapered surface 34 oi the packer bore andthe mandrel wedge surni e".- Whenthefdevice'is thus set within the coupling, with" the parts in the position shown inc, Fig. 2, the circulation passage or the drill string is 'eiiectiveLv plugged against upward fluid leakage, and the check valve 23 then serves in the capacity of a back pressure valve.

nom the invention 1 scope;

, The device may readily be removed from the coupling after the drill string is pulled iromthe well, simply by disconnecting the coupling l3 from the pipe, removing bushing 48, and then driving the mandrel downwardly to release the slips, by means of apiece of wood or other implement inserted within-the upper end of the coupling bore. As the mandrel is driven down, the packer is released and the entire assembly may be withdrawn through the lower end of the coupling.- In Fig; 3 I show a variant form of means for arresting downward movement of the device, to be Qused in Y situations where a special coupling l3 may not be employed, or where there is no provision of afixed stop suchas the bushing 38. The

device'niay be positioned and set within a couplirig by providing on the lower endoi the body an extension adapted to engage, a stationary member in the pipe string,'for example a part 'of the usual back pressure valve, to arrest downward travel of thedrop-in assembly, the length or the extension being predetermined in accordance with the distance betweenflthe back pressure valve and the coupling so that the drop-in plug will be. positioned for setting within the coupling. Referring tojig. 3, the'body 26 carries on its lower .end a rod threaded at ll into the body bore .52. 'As the drop-in device reaches setting position, the lowerend oi the rod engages shoulder 19a below'inclined lwall IQ of the'baclr' pressure valve, to arrest downward movement of the device,the'length oi the rod being such that at the point of arrest-the packer 33 and pipe engaging means 34 will be positioned for expansion within thecoup nfl'. all as 'previously'described. a v

The drawing is. to be regardedmerely as illustrative oi the invention in certain .oi its'typical and preferred forms,since various changes and modifications 'inaybe made without departure I claim:

' A back-pressure valve device adapted tobe in its I intended spirit and portion-oi said pipe to arrest downwardmove-g ment-of'the device therein. a 2'. A back pressure valve device adapted to' be dropped within a'well pipe, comprising an elongated body containing afluid passage, radially expansible pipeengagingelements, a carrier'ior said elements surrounding saidgbodyiand movable longitudinallyv relative 'thereto, fa packer] surrounding said body and expansible into'fluid tight engagement by upward relative movement of' the body and valve means preventing upward fluid flow throughsaid passage.

'3. A back pressure valve device adapted to be [dropped within awell pipe, comprising an eionf gated body containing a, fluidfpassage radially expansible pipeeng'aging elements,.acarrier for, said elements surrounding saidbody and movable longitudinally. relative thereto,, a packer surrounding said body and expansible into fluid pered surface within and bearing against said packer, and valve means preventing upward fluid flow through said passage.

tight engagement by upward relative movement a .,of the; body, said.;body,-,having an upwardly tasure device'adapted to be dropped within said pipe string, said device comprising, a body containing a passage adapted to conduct fluid downwardly through said device, a valve' closing said passage against upward fluid flow, a'packer carmeans for holding the device against upward movement in said string, and means independent of said engaging'm'eans for arresting downward movement of said device at a point at which said packer and pipe engaging means are positioned within the bore of said coupling;

5. In combination with a well pipe stringcontaining a coupling near its lower end, a pipe closure device adapted to be dropped within said pipe string, said device comprising a body containing a passage adapted to conduct fluid downwardly through said device, a valve closing said passage against upward fluid flow, a packer carried by said body, and expansible pipe engaging means for holding the device against upward movement in said string, and means for arresting downward movement of said device at a point at which said packer is positioned within the bore of said coupling, said means comprising an annular shoulder carried by the coupling, said shoulder having smaller internal diameter than the coupling bore and being engageable by a shoulder onsaid closure device.

6. In combination with awell pipe string containing a coupling near its lower end, serrations formed in the coupling bore wall, a pipe closure device adapted to be dropped within the pipe string, said device comprising expansible wedge slips adapted to engage said serrations to hold said device against upward movement in the pipe string, and a packer expansible into fluid tight engagement with the coupling bore wall when said serrations are engaged by the slips.

'7. In combination with a well pipe string containing a coupling near its lower end, serrations formed in the coupling bore wall, a pipe closure device adapted to be dropped within the pipe string, said device comprising expansible wedge slips adapted to engage said serrations to hold said device against upward movement in the pipe string, and a packer expansible into fluid tight engagement with the coupling bore wall when said serrations are engaged by the slips, and an annular stop at the lower end of said coupling and engageable by said device to arrest its downward travel.

8. A back pressure valve device adapted to be dropped within a well pipe, comprising a continuous elongated body mandrel, radially expansible means movable longitudinally of said mandrel and adapted to engage said pipe to hold the device against upward movement therein, and a radially expansible pipe engaging packer surrounding said mandrel and having an upwardly tapering bore receiving a correspondingly shaped portion of the mandrel, said mandrel being upwardly movable by fluid pressure to radially expand both the pipe engaging'means and the packer.

9. In combination with a well pipe string containing a coupling near its lower end, a pipe closure device adapted to be dropped within said pipe string, said device comprising a body, an expansible packer, pipe engaging means for holding the device against upward movement in said string, and means on the coupling and acting independent of said pipe engaging means for ,arrestin wnward movement of said ody at a point at which said packer is positioned within the bore of said'coupling. 2 10. In combination with a well pipe string containing a coupling near its lower end a pipe closure device adapted to be dropped within said 7 I pipe string said device comprising a body, an ried by said body, and expansible pipe engaging expansible packer, expansible pipe engaging means for holding the device against upward movement in said string, and means on the coupling and acting independent of said pipe engaging means for arresting downward movement of said device' ata point at whichsaid packer and pipe engaging means-are positioned within the boreo f said coupling, said pipe engaging means being expansible into engagement within said coupling bore by virtue of upward movement of the body from said point.

11. In combination with a well pipe string containing a coupling near its lower end, a pipe closure device adapted to be dropped within said pipe string, said device comprising a packer and expansible pipe engaging means for holding the device against upward movement in said string, and means independent of said engaging means for arresting downward movement of said device at a point at which said packer is positioned within the bore of said coupling, said means comprising an annular stop shoulder projecting inwardly from the wall of the coupling bore at its lower end and engageable by a shoulder on said closure device.

12. In combination with a well pipe string containing a series of upper couplings and a lower tubular coupling above the bottom end of the pipe string, the bore of said lower coupling having a recess formed in its wall, a pipe closure device adapted to be dropped within said pipe string and through the upper couplings into said lower coupling bore, said device comprising a body having a fluid passage extending longitudinally therethrough, a valve closing the passage against upward fluid flow, a packer carried by the body, and means for holding said body in predetermined position within said bore with the packer positioned therein, said means including radially movable means mounted on the body outside and opposite said fluid passage and engageable within said recess by movement of said device into the coupling bore, and means for radially expanding said packer by virtue of upward movement of the body while said radially movable means is engaged within said recess.

13. In combination with a well pipe stringcontaining a series of upper couplings and a lower tubular coupling above the bottom end of the pipe string, the bore of said lower coupling having a recess formed in its wall, a pipe closure.

device adapted to be dropped within said pipe string and through the upper couplings into said lower coupling bore, said device comprising a body having a fluid passage extending longitudinally therethrough, a valve closing the passage against upward fluid flow, a packer carried by the body, and means for.holding said body in predetermined position within said bore with the packer positioned therein, said means ineluding radially movable means mounted on the body and engageable within said recess by movement of said device into the coupling bore, and wedge means carried by the body and operable by fluid pressure below said device to wedge against and radially expand said packer into fluid tight engagement with the coupling bore wall.

14. A pipe closure device adapted to be dropped within a well pipe, comprising a body, a sleeve surrounding and mounted on said body for vertical movement relative thereto, a member movable radially within a way formed in said sleeve into engagement with said pipe, and a packer 16. In combination with a well pipe string containing a series of upper couplings and a lower tubular coupling above the bottom end of the pipe string, a pipe closure device adaptedto-be dropped within said pipe string and through the upper couplings into said lower coupling bore, said device comprising a body having a fluid passage extending longitudinally therethiough, a valve closing the passage against upward iluid flow, a packer carried bjythe' body, and means for arresting downward movement of the device'at a predetermined position within said bore with the packer positioned therein, said means including an upwardly facing, shoulder within the coupling, and meanson said device positioned outside and opposite said fluid passage and engageabie with said shoulder.

ALBERT L. B'IONE. 

